Bioactivity guided fractionation of the seeds of Allanblackia floribunda Oliv. (Guttiferae)

Abstract

Six phenolic compounds previously isolated from the seeds of Allanblackia floribunda and identified as (1) Gb-2a glucoside (naringenin-1,3-II,8-eriodictyol glucoside), (2) Morelloflavone glucoside, (3) Gb-2a(naringenin-1,3-II,8-eriodictyol), (4) Volkensiflavone, (5) Morelloflavone and (6) Volkensiflavone glucoside were evaluated for their anti-inflammatory, anti-hyperglycemic and antibacterial activities. Their anti-inflammatory activity was evaluated using Heat induced hemolysis assay and inhibition of albumin denaturation technique, anti-hyperglycemic activity was evaluated using α-amylase and α-glucosidase inhibition assay and antibacterial activities were also evaluated for both gram positive and gam negative bacteria using the micro titer discs. All isolates showed a significant inhibition against the activities of α-amylase and so they have a good potential in the alleviation of post prandial hyperglycemia. Gb-2a glucoside, morelloflavone glucoside and morelloflavone showed better ability to protect the human erythrocyte membrane against lysis compared to Gb-2a, Volkensiflavone and its glucoside. Morelloflavone glucoside showed positive activity against Staphylococcus aureus, Escherichia coli and Mycobacterium smegmatis even though the control drug Kanamycin was more potent (0.137± 0.00, 0.12± 0.00 and 0.13± 0.00 mg/ml). Gb-2a, Morelloflavone and their glucosides showed significant anti-inflammatory, hypoglycemic and antibacterial activities. This explains the use of Allanblackia floribunda traditionally for the alleviation of pains and infection.

Keywords:

Allanblackia floribunda, morelloflavone, volkensiflavone, Gb-2a, anti-inflammatory, antibacterial.